Science: An Epic Find

For the sheep and dairy farmers of northeastern Scotland, the summer of
1976 was unusually harsh. Prolonged drought had parched the
countryside, ruining crops and turning flourishing grasslands into
brownish straw. But for archaeologists of the Royal Commission on the
Ancient and Historical Monuments of Scotland, the dry spell was
something of a bonanza. It had created ideal conditions for observing
so-called crop marks, telltale patches on the ground that usually
indicate buried remains of ancient building, farming or other activity.
Flying over the...